From the National Post (Canada), Thursday, March 12, 2009:
...On Tuesday, the UN Security Council sanctions-monitoring committee rebuked Iran for trying to smuggle a vast shipload of arms to Syria in violation of at least five UN resolutions. The discovery of over 3,000 cases of high explosives, large-bore armour-piercing shells and anti-tank propellant proves Iran has no intention of ceasing its arms shipments to terror groups such as Hezbollah, using Syria as a conduit. Nor can it be trusted to honour its international agreements to forgo acquiring nuclear arms...
...This is not, of course, the first time Iran has been caught red-handed smuggling powerful weapons to terror groups it funds and trains. In January, 2002, a Palestinian ship, the Karine A, was caught by the Israelis in the Red Sea crammed full of Iranian-and Russianmade weapons. Many of the munitions used by Iraq's insurgents over the past seven years have been stamped "Made in Iran" and several times since the end of the Hezbollah-Israel war in the summer of 2006, convoys carrying Iranian weapons have been spotted resupplying the terrorists overland from Syria.
All of this violates a string of Security Council and General Assembly resolutions going back to 2004 and before. Five years ago, the UN unanimously adopted a resolution upholding the independence and territorial integrity of Lebanon. In particular, Resolution 1559 called for the disarmament and dismantling of private militias such as Hezbollah. Iran ignored the edict, as did Syria.
Indeed, the two continue to meddle in Lebanese internal politics so as to keep that nation open as a staging area for terror attacks on Israel. And they do so despite the presence of 15,000 UN peacekeepers in Lebanon.
By some estimates, Iran has rearmed Hezbollah with more than two million rounds of ammunition and thousands of mortars and rockets since the UN brokered an end to the 2006 Hezbollah-Israel conflict, a deal that forbad Iran from re-equipping the Shiite radicals.
All this establishes not only why Iran cannot be trusted (and why the U. S. and other Western nations must closely monitor and constrain Iran's actions), but also why Israel is right to counteract threats to its security from places such as Gaza.
The Jewish state's neighbours, starting with Iran, have no interest in playing nice.